DB integration: initial support. user login by DB.

src/db.h

@@ -0,0 +1,12 @@
+typedef struct {
+    char *name;
+    char *pass;
+} i_auth_t;
+
+typedef struct {
+    char privileges;
+    int is_logged;
+} o_auth_t;
+
+int init_connection();
+int db_user_auth(i_auth_t *credentials, o_auth_t *response);